Re: [Implementation] Calling wrapped functions, converters, policies

David Abrahams wrote:
> [Aleksey, please see below w.r.t. lambda exprs]

[...]

> >> I have no problem in principle (I think) with bidirectional
> >> converter *generators*, but bidirectional converters won't work.  They
> >> need completely different data members, and from-XXX converters need
> >> to be 2-phase for overloading, while to-XXX converters are one
> >> phase.  In other words, I have no problem with:
> >> [snip]
> >
> > OK agreed. So, should the nested member be a metafunction class?
> >
> >    some_generator
> >    {
> >        typedef /* to converter */ to;
> >        typedef /* from converter */ from;
> >    };
>
> Well, it can be more efficient than using any generalized lambda expr,
> but it's also more work for the user.  AFAIK MPL is going to change so
> that apply<...> uses lambda<...> internally,

That was the plan (to be honest, I am having second thoughts, but we'll see
how it works out).

> but I guess there would
> always be a lower-level apply_metafunction_class<...> for efficiency.

For sure.

> Even though we've written about that in our book, it's not implemented
> yet.  Aleksey, care to comment?

Yep, not yet.

Aleksey


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